Gordon Brown yesterday ordered a massive security sweep amid fears that computer-held data in ALL government departments could be at risk.

The review follows the incredible loss by HM Revenue and Customs of two CDs holding personal and financial details of 25million people in families claiming child benefit.

There are now concerns that the security of other sensitive information affecting millions more people is also threatened. Most at risk are NHS medical records and Department of Work and Pensions details.

There are also worries that the new £224million ContactPoint database - a list containing details and addresses of every child in England - could fall into the hands of paedophiles.

Commenting on the fiasco for the first time, Mr Brown told MPs yesterday: "I profoundly regret and apologise for the inconvenience and worries caused to millions of families.

"When mistakes happen in enforcing procedures, we have to do all we can to protect the public. We are taking all action that is necessary."

Embarrassed Mr Brown announced a review by the Cabinet Secretary of data safety in government.

It will make sure rules are in place to stop officials downloading sensitive information.

Information Commissioner Richard Thomas will also be given powers to carry out spot checks.

But last month Mr Brown REJECTED calls made by a Lords committee in the summer for random security audits.

On October 25, a week after the child benefit CDs went missing, a Government spokesman said: "The current enforcement regime for data protection is fit for purpose."

The fallout from the biggest data breach of security in British history continued yesterday with Chancellor Alistair Darling admitting the confidence of the Government had been rattled by the scandal.

He said: "Of course it shakes confidence. But I'm not going to run. It's difficult and it's unwelcome. But I'm determined to see it through."

As nearly 10,000 people rang the HMRC child benefit hotline to seek information about data loss, David Cameron said families were "desperately worried" about the crisis.

Labour MPs feared support for Mr Brown's government was collapsing.

They likened the crisis to the Tories' Black Wednesday when the party lost its reputation for economic competence. Worried backbenchers said plans to introduce ID cards should be put on the back-burner.

Karen Buck, of the Commons Home Affairs Committee, said: "The worst thing in the world would be to plough on and say 'We're going ahead'."

Andy Love, of the Treasury Committee, said: "I'd like to see them reassuring the public they have the ability and the software to be able to secure the national identity register."

But No10 said: "There has been no change in the plans."

In defiance of procedures, a junior HMRC official in Tyne and Wear sent the two unencrypted child benefit CDs by TNT courier to the National Audit office in London.

The discs were not recorded or registered and have not been seen since.

Yesterday unions said that pressure imposed on staff after thousands of job cuts meant the blunder was an accident waiting to happen.

Calling for an end to plans to cut a further 12,500 HMRC posts, the Public and Commercial Service Union said: "It was inevitable that something like this was going to occur."

Workers at the nearby DSS Longbenton plant in Newcastle claimed that cuts had forced employees to use internal mail or second class post rather than registered post or recorded delivery.

One said: "We are constantly told that registered post and recorded delivery are too expensive. All mail must be dealt with internally."

The loss of the discs has raised fears of massive ID theft.

Yesterday credit reference agency Experian warned that millions of youngsters, especially those now aged 15-17, could be at risk for years.

It said: "Fraudsters will wait until they turn 18 then start applying for loans and cards in their names.

"That could have a catastrophic effect on the victims' future ability to get on the housing ladder, rent a flat, or obtain a credit card or loan."

Despite the fears, there was no rush yesterday to close accounts.

Payments body APACS, said: "There were a higher number of calls than usual first thing in the morning.

"But by 11am the major banks were all reporting business as usual."

Former HMRC chairman Paul Gray, who resigned over the CD blunder, will receive his pension in full.